Automated spacer frame fabrication

Abstract

Method and Apparatus for fabricating a spacer frame for use in an insulating glass unit. One of a multiple number of possible spacer frame materials is chosen for the spacer frame. An elongated strip of the material is moved to a notching station where notches are formed at corner locations. The character of the notches is adjusted based on the selection of the metal strip material and more particularly to achieve bending of the material in an repeatable, straightforward manner. Better control over the notching process is also achieved by exhaust flow control of a double acting cylinder. A positioning spacer achieve very accurate side to side positioning of a die and anvil to precisely notch and deform the metal strip. Downstream from the notching station the metal strip is bent into a channel shaped elongated frame member having side walls. Further downstream a leading strip of channel shaped material is severed or separated from succeeding material still passing through the notching and bending station.

The invention claimed is: 
     
       1. Apparatus for fabricating multiple spacer frames from an elongated metal strip for use in fabricating insulating glass units, said apparatus comprising:
 a) a punching station having a punch drive positioned with respect to a path of travel of the elongated metal strip for moving a die toward and away from the elongated metal strip into and out of contact with a flat surface of the elongated metal strip at controlled locations along a length of said elongated metal strip to form a notch which extends inwardly from an edge of the elongated metal strip and to deform a surface of the elongated metal strip contacted by the die and thereby form a weakened zone adjacent to the notch in the elongated metal strip at spacer frame comer location; 
 b) a channel forming station positioned with respect to the path of travel of the elongated metal strip for bending the elongated metal strip to include side walls; 
 c) a severing station positioned with respect to the path of travel of the elongated metal strip for separating a lead, spacer frame defining portion of the elongated metal strip from said elongated metal strip after the lead, spacer frame defining portion of the elongated metal strip has moved through the punching and channel forming stations; and 
 d) said punching station comprising a control for adjusting energy transferred from the die to the elongated metal strip during contact between the die and the elongated metal strip to form said weakened zone based upon a composition of the elongated metal strip. 
 
     
     
       2. The apparatus of  claim 1  wherein the channel forming station comprises a roll former for bending the strip stock to form a U shaped channel. 
     
     
       3. The apparatus of  claim 1  additionally comprising, an uncoiling station comprising multiple coils of metal strip stock and wherein a first coil of metal strip stock is unwound to form a first elongated metal strip having a first composition and wherein a second coil of metal strip stock is unwound to form a second elongated metal strip having a second composition, said second composition different from the first composition. 
     
     
       4. The apparatus of  claim 1  wherein the die moves in response to actuation of said punch drive to contact said elongated metal strip to form the weakened zone of the spacer frame corner location and further comprising a second die which moves in response to actuation of said punch drive to contact the elongated metal strip and form a second weakened zone at the spacer frame corner location. 
     
     
       5. The apparatus of  claim 1  additionally comprising a die support supporting the die for movement in response to actuation of the punch drive and wherein the control comprises a stop having a contact region that engages the die support to limit movement of the die and wherein a position of the contact region of the stop is adjusted based upon the composition of the elongated metal strip. 
     
     
       6. The apparatus of  claim 1  wherein the punch drive comprises a dual acting air driven actuator having an output coupled to the die, said actuator comprising an actuator body having first and second pressure chambers wherein a first pressure chamber, when controllably pressurized, moves said die into contact with a flat surface of the elongated metal strip to deform the elongated metal strip and form the weakened zone and further wherein the second chamber, when controllably pressurized, moves the die away from the elongated metal strip subsequent to deformation by said die; and further wherein said control comprises a solenoid valve for alternately pressurizing the first and second chambers of the actuator, a controller for operating the solenoid valve, and a combination of a quick exhaust valve and flow control valve coupled to said actuator body for allowing air to exhaust from the second pressure chamber of said actuator at a controllable rate. 
     
     
       7. Apparatus for fabricating spacer frames from an elongated metal strip as the elongated metal strip moves along a path of travel, said apparatus comprising:
 a) a punching station having a die and a punch drive, the punch drive comprising a dual acting air driven actuator having an output coupled to the die, the actuator comprising an actuator body having first and second pressure chambers wherein a first pressure chamber, when controllably pressurized, moves said die into contact with a flat surface of the elongated metal strip to deform the elongated metal strip and form a weakened zone at multiple spacer frame corner locations along a length of said elongated metal strip and further wherein the second chamber, when controllably pressurized, moves the die away from the elongated metal strip subsequent to deformation by said die; 
 b) a bending station for bending the elongated metal strip into a channel shape; 
 c) a severing station for separating a lead spacer frame defining portion of the elongated metal strip from said elongated metal strip after the lead spacer frame defining portion has moved through the punching and bending stations; and 
 d) a controller comprising a solenoid valve for periodically pressurizing said first chamber of the actuator to actuate the punch drive to form the weakened zone at the multiple spacer frame corner locations along the length of the elongated metal strip as said metal strip moves through the punching station and wherein a combination of a quick exhaust valve coupled to the actuator body and a flow control valve is coupled to an exhaust port of said quick exhaust valve for providing an air passageway to exhaust air from the second chamber at a controllable rate as said solenoid valve pressurizes the first chamber; 
 e) said punching station comprising an adjustable stop that limits movement of the punch drive by an amount that is adjustable based on the composition of the elongated metal strip to control deformation of the elongated metal strip by the die in producing the weakened zone. 
 
     
     
       8. The apparatus of  claim 7  wherein the adjustable stop comprises a specified thickness stop mounted to a support. 
     
     
       9. The apparatus of  claim 8  wherein the specified thickness stop is a magnetic material and the support includes a magnet to attract the specified thickness stop. 
     
     
       10. Apparatus for fabricating spacer frames from an elongated metal strip moving along a path of travel, said apparatus comprising:
 a) a punching station comprising:
 i) first and second dies for contacting the elongated metal strip to form notches which extend inwardly from edges of the elongated metal strip and for deforming a surface of the elongated metal strip to form first and second weakened zones adjacent to the notches in said elongated metal strip to facilitate bending of the elongated metal strip into a closed sided spacer frame; 
 ii) a die actuator assembly comprising first and second die supports that support the first and the second dies for movement toward and away from the elongated metal strip; said die actuator assembly comprising a punch drive for simultaneously moving the first and second dies into contact with the elongated metal strip to notch the elongated metal strip and deform said elongated metal strip to form the first and second weakened zones; and 
 iii) first and second adjustable stops position on opposite sides of the path of travel of the elongated metal strip and having first and second contact regions, respectively, positioned in relation to the die actuator assembly so that the first contact region of the first adjustable stop is contacted by the first die support and the second contact region of the second adjustable stop is contacted by the second die support as the punch drive moves the first and second dies into contact with the elongated metal strip to deform the strip and form the first and second weakened zones; wherein, energy transferred to the elongated metal strip by the first and second dies is controlled by adjustment of a position of said first and second contact regions in relation to the die actuator assembly based oil a composition of the elongated metal strip; 
 
 b) a bending station for bending the elongated metal strip into a channel having two side walls wherein one side wall includes a first of said weakened zones and a second side wall includes a second of the weakened zones to facilitate bending of the channel in a region of said first and second zones; 
 c) a severing station for separating a lead, spacer frame defining portion of the elongated metal strip from said elongated metal strip after the lead, spacer frame defining portion has moved through the punching and bending stations; and 
 (d) a controller for actuating the punch drive of the die actuator assembly to form the first and second weakened zones in said elongated metal strip. 
 
     
     
       11. The apparatus of  claim 10  wherein the punching station additionally comprises first and second anvils defining a slot which accommodates movement of the elongated metal strip through the punching station. 
     
     
       12. The apparatus of  claim 10  wherein the first and second dies each comprise a notching die portion for removing a first metal portion from the elongated metal strip and a deforming die portion for deforming a second metal portion of the elongated metal strip. 
     
     
       13. The apparatus of  10  wherein the first and second stops each comprise a first, constant thickness portion and a second, removable portion attached to the constant thickness portion wherein a thickness of the removable portion is adjusted to control movement of the first and second dies and therefore deformation of the strip. 
     
     
       14. The apparatus of  claim 13  wherein the removable portion of each of said first and second stops comprises a magnetic material and defines an opening which fits over a stud in said constant thickness portion of said first and second stops. 
     
     
       15. The apparatus of  claim 10  wherein each of the first and the second dies comprises a sharp edged ridge which help deform the elongated metal strip when the elongated metal strip is impacted by the first and second dies to form the first and second weakened zones. 
     
     
       16. Apparatus for fabricating spacer frames from an elongated metal strip moving along a path of travel, said apparatus comprising:
 a) a punching station comprising i) a dual acting air powered actuator including first and second pressure chambers; ii) a die assembly coupled to the air powered actuator and comprising, a die mounted for up and down movement wherein pressurization of the first pressure chamber produces a downward stroke of the actuator to move the die downward into contact with a surface of the metal strip steak to form a weakened zone at spacer frame corner locations along a length of said elongated metal strip and further wherein pressurization of the second chamber by pressurized air retracts the die upward away from the metal strip; iii) a quick exhaust valve for delivering pressurized air to the second chamber during an actuator return stroke as the actuator retracts the die and exhausting air from said second chamber as pressure in the first chamber moves the die downward into contact with the elongated metal strip and iv) a flow control valve coupled to an exhaust port of the quick exhaust valve for relieving pressure at a controlled rate from the second chamber of said air powered actuator as air is pressurizing said first chamber of said air powered actuator, 
 b) a bending station for bending the metal strip into a desired shape; 
 c) a severing station for separating a lead spacer frame defining portion of the elongated metal strip from the elongated metal strip after the lead spacer frame defining portion has moved through the punching and bending stations, and 
 d) a controller for actuating the dual acting fluid powered actuator at multiple spacer frame corner locations as the elongated metal strip moves along the path of travel. 
 
     
     
       17. The apparatus of  claim 16  wherein the flow control valve comprises a flow restrictor having an orifice extending therethrough and an adjustment for opening and closing said orifice. 
     
     
       18. Apparatus for fabricating multiple spacer frames horn an elongated metal strip as the elongated metal strip moves along a path of travel said apparatus comprising:
 a) a punching station comprising:
 i) an upper die and a lower die for deforming the elongated metal strip through contact with the upper and lower dies to form a weakened zone in the elongated metal strip that facilitates bending of the elongated metal strip; 
 ii) an upper die support mounted for movement in a transverse direction to the path of travel of the elongated metal strip for positioning the upper die relative to the path of travel of the elongated metal strip; 
 iii) a lower die support coupled to the upper die support for movement in said transverse direction relative to the path of travel of said elongated metal strip; 
 iv) an upper guide supporting the upper die support for movement in the transverse direction; 
 v) a lower guide supporting the lower die support for movement in the transverse direction; 
 vi) a punch drive coupled to the upper die support for driving the upper die into contact with the elongated metal strip; 
 vii) an adjustable stop coupled to the lower die support and positioned for contact with the upper die support as said punch drive moves the upper die into contact with the elongated metal strip wherein a position of contact between the adjustable stop and upper die support controls deformation of the elongated metal strip to form the weakened zone; 
 viii) a reference post moveable with respect to the path of travel and defining a reference surface; and 
 ix) an adjustable spacer including a spacer body having first and second end surfaces spaced apart by an adjustable distance and trapped between the reference surface of the reference post and the lower die support for positioning of the upper and lower dies relative to the path of travel of said elongated metal strip; 
 
 b) a roll forming station for bending the strip into a desired shape; and 
 c) a severing station for separating, a lead, spacer frame defining portion of the elongated metal strip from the elongated metal strip after the lead, spacer frame defining portion has moved through the corner punching and roll forming stations. 
 
     
     
       19. The apparatus of  claim 18  additionally comprising an elongated connector that extends through the post to engage the lower die support to wedge the adjustable spacer between the post and said lower die support. 
     
     
       20. The apparatus of  claim 19  wherein the elongated connector passes through said body portion of the adjustable spacer. 
     
     
       21. The apparatus of  claim 18  wherein the body of the adjustable spacer comprises:
 i) a first body portion having a first outer cylindrical surface basing a first diameter and a second outer cylindrical surface having a second diameter greater than the first diameter, said first body portion having a stepped region between the first and second outer cylindrical surfaces that forms an abutment, 
 ii) a cylindrical sleeve that fits over the first outer cylindrical surface of the first body portion, and 
 iii) one or more annular spacers that fit over the outer cylindrical surface of the first body portion between one end of the sleeve and said abutment and define a distance between the first and second ends of the adjustable spacer. 
 
     
     
       22. Apparatus for fabricating spacer frames from elongated metal strips, said apparatus comprising:
 a) a punching station comprising first and second punch drives spaced apart along a travel path of the elongated metal strips and first and second dies for contacting a surface of the elongated metal strips to form a plurality of spaced apart weakened zones at corner locations along said elongated metal strips, wherein the first punch drive is coupled to the first die for moving the first die into contact with a surface of the elongated strips at a first location and wherein the second punch drive is coupled to the second die for moving the second die into contact with a surface of the elongated metal strips at a second location spaced along the path of travel from the first location; 
 b) a channel forming station positioned with respect to the travel path of the elongated metal strips for bending the elongated metal strips to a channel having side walls; 
 c) a severing station positioned with respect to the travel path of the elongated metal strips for separating a lead spacer frame defining portion of the elongated metal strips after the lead spacer frame defining portion has moved through the punching and channel forming, stations; and 
 d) a control station for activating only the first punch drive to cause the first die to contact elongated metal strips having a first composition to form said plurality of spaced apart weakened zones and for activating only the second punch drive to cause the second die to contact elongated metal strips having a second composition to form said plurality of weakened zones, wherein said second composition is different from the first composition.